Steady yellow engine light; code reads P5099; internet says this code is for high (presumably resistance) in the thermostat electrical circuit, article says this usually indicates failed thermostat. I think "great! the last time I replaced a thermostat it was $15 and took 26 minutes. Wait, this is a MINI and everything is special.

Engine light was on for four days and then didn't light up when I started the car this morning, Car seems to be running fine, no noticeable leaks or noises. Is there any possibility that the thermostat is in the process of failing?

Does anyone know whether the thermostat is covered under the extended warranty?

I have a 2000 mile road trip scheduled next week, how worried should I be?

 

If your going on a trip of that distance I would have things checked out! Having trouble on the road wouldn't be no fun! Check all your fluids and take it to the dealer.